The present invention relates to an image information output apparatus, and more particularly to an image information output apparatus designed to output the luminance data of a specified region of a picked-up image so as to be superposed upon this picked-up image.
In the field of image information output apparatuses, a video measuring system has recently been developed. This video measuring system is used to set a single vertical luminance line at a given position on the image screen and to pickup image data on the vertical luminance line, thereby measuring the width or darkness and lightness of the surface of an object to be photographed. However, the prior art video measuring system is constructed such that the image data is picked up with respect to the single vertical line. Therefore, when a video camera is defective and noise is mixed into the image information, the image data of an image portion corresponding to such noise components is mixed into the image; errors thus occur in the signal processing, and a precise measurement cannot be made.
To cope with these problems the position of the vertical line is moved stepwise in the horizontal direction, and luminance data is extracted at a plurality of vertical positions, and an average value of those data is determined by, for example, a data processor which permits this value to be displayed on a monitor. However, where such countermeasures are taken, a microprocessor and a memory of large capacity are required to process the data corresponding to the plurality of vertical positions, resulting in a large and complicated video measuring apparatus as well as in an increased manufacturing cost.